Gyroscope

Abstract

A miniature gyroscope having a gas-turbine reaction rotor of dumb-bell form which comprises a pair of masses (62,63) one spaced from the other at opposite ends of a shaft, and an inner gimbal (61) which extends into the space between the two masses and there provides a rotational mounting for the rotor, and means (42) for feeding to the rotor, through the space between the pair of rotor masses, gas to be discharged from the rotor to cause it to spin.

We claim: 
     
       1. A gyroscope having a gas-turbine reaction rotor which comprises a pair of masses, one spaced from the other at each end of a shaft, and an inner gimbal which extends into the space between the two masses and there provides a rotational mounting for the masses, and means for feeding to the rotor, through the space between the pair of rotor masses, gas to be discharged from the rotor to cause it to spin. 
     
     
       2. A gyroscope as claimed in claim 1 including an outer gimbal provided with first and second co-axial spigots, one on each side of the rotor and mounted in bearings for rotation of the outer gimbal with movement of the rotor. 
     
     
       3. A gyroscope as claimed in claim 2 including means for sensing relative rotation between one of the first and second spigots and a structure in which the spigot is mounted. 
     
     
       4. A gyroscope as claimed in claim 1 including an outer gimbal provided with a single spigot mounted in a bearing arrangement so that the rotor and its gimbals are mounted on the bearing arrangement in cantilever fashion. 
     
     
       5. A gyroscope as claimed in claim 4 including means for sensing relative rotation between the single spigot and a structure in which the spigot is mounted. 
     
     
       6. A gyroscope as claimed in claim 1 additionally comprising solid propellant material and an ignition capsule to ignite the material to provide by combustion of the propellant material the propellant gas when required. 
     
     
       7. A gyroscope as claimed in claim 6 wherein the means for feeding gas to the rotor comprises a gas injection needle mounted in the structure which houses the gyroscope and being movable relative to the rotor between an engaged disposition, in which the tip of the needle is engaged with the inner gimbal for delivery of the gas to the inner gimbal, and serving also to cage the gyroscope until the rotor is spinning, and a disengaged disposition, in which the tip of the needle is disengaged from the inner gimbal so that the gyroscope is not caged by the engagement of the needle with the inner gimbal. 
     
     
       8. A gyroscope as claimed in claim 7 wherein the needle is straight and moves by translation between its engaged and disengaged dispositions, in a direction along its length, the needle lying on the axis of rotation of the outer gimbal and being fixed against rotation in the structure housing the gyroscope, the engagement of the needle and the inner gimbal being such as to prevent rotation of the inner gimbal relative to the needle. 
     
     
       9. A gyroscope as claimed in claim 8 wherein the said engagement of needle and inner gimbal is between a pin in the gimbal transverse to the length of the needle and a slot in a forked tip of the needle. 
     
     
       10. A gyroscope as claimed in claim 7 wherein the gas injection needle is spring-biased out of engagement with the inner gimbal, but is held in engagement during delivery of the propellant gas by the pressure of said gas. 
     
     
       11. A gyroscope as claimed in claim 10, wherein the needle is held in engagement with the inner gimbal, until ignition of the propellant material, by a mechanical link between the needle and structure housing the rotor, which link is destroyed by the combustion of the propellant material. 
     
     
       12. A gyroscope as claimed in claim 10 wherein the needle is held in engagement with the inner gimbal, until ignition of the propellant material by use of the propellant material, itself to transmit from the structure which houses the rotor a force of reaction to the force of the spring-bias of the needle.